Long-term evaluation of bulking agents for the treatment of fecal incontinence: clinical outcomes and ultrasound evidence

BACKGROUND:The injection of bulking agents into the anal canal has been reported to help patients with fecal incontinence. Although it has been advocated as a safe and effective option, substantial data concerning long-term efficacy are still lacking, and the resorption process of the implants has not yet been carefully studied. The aim of our study was to investigate the long-term outcomes of bulking agents for the treatment of fecal incontinence and the behavior of implanted materials in the anorectum. METHODS: At a median follow-up of 7 years, 19 patients with idiopathic fecal incontinence who had received bulking agent implants were evaluated. Clinical, manometric and ultrasound assessments were carried out. RESULTS: The clinical improvements that were achieved in the short term were not maintained over time. For each patient, the number of implants that could no longer be identified on ultrasound was significantly correlated with poorer clinical long-term outcomes. On average, only 14 % of the originally injected volume was still detectable. CONCLUSIONS: In the long term, perianally injected bulking agents seem to lose effectiveness. The ultrasound assessment suggests that the process of resorption is almost complete, and the implants are no longer effective in treating incontinence.